"Barack knows the American Dream because he's lived it," she told the Democratic National Convention on Tuesday in an address intended to reassure voters that her husband share their values — hard work, perseverance and optimism — while also drawing a contrast between him and Mitt Romney.

She never mentioned the U.S. president's Republican challenger, who grew up in a world of privilege and wealth.

But the point was clear as she weaved a tapestry of their early years together, when money was tight and times were tough, when they were "so in love, and so in debt." She reminisced about the man who now occupies the Oval Office pulling his favorite coffee table out of the trash and wearing dress shoes that were a size too small. And she told stories about a president who still takes time to eat dinner with his daughters nearly every night, answering their questions about the news and strategizing about middle-school friendships.

With a mix of personal anecdotes and policy talk, the speech was her most political yet.

"Today, after so many struggles and triumphs and moments that have tested my husband in ways I never could have imagined, I have seen firsthand that being president doesn't change who you are — it reveals who you are," she said.

To that send, she painted a portrait of a leader who knows first-hand the struggles of everyday Americans, who listens to them as president, and who pushes an agenda with their interests in mind.

"That's the man I see in those quiet moments late at night, hunched over his desk, poring over the letters people have sent him," she said. "I see the concern in his eyes … and I hear the determination in his voice as he tells me, `You won't believe what these folks are going through, Michelle . it's not right. We've got to keep working to fix this. We've got so much more to do."

Her speech followed an evening of addresses by top Democrats, who ridiculed Republican Mitt Romney as a millionaire candidate for president who "quite simply doesn't get it" and worse on Tuesday, opening night of a national convention aimed at propelling Barack Obama to re-election despite high unemployment and national economic distress.

Obama "knows better than anyone there's more hard work to do" to fix the sputtering economy, said San Antonio Mayor Julian Castro, the convention keynote speaker.

Delegates cheered as a parade of speakers extolled Obama's support for abortion rights and gay marriage, for consumer protections enacted under his signature health care law and for the auto industry bailout he won from Congress in his first year in office.

"He said he'd take out bin Laden, and with our great SEAL team, he did," declared former Virginia Gov. Tim Kaine in one of several references to the military raid that ended the life of the terrorist mastermind behind the attacks of Sept. 11, 2001.

The crowd cheered even louder when the subject turned — dismissively — to Romney.

"If Mitt was Santa Claus, he'd fire the reindeer and outsource the elves," former Ohio Gov. Ted Strickland said in a biting speech.

After the deep recession, Castro said in excerpts released in advance of his speech, the nation is making progress "despite incredible odds and united Republican opposition."

He declared that 4.5 million jobs have been created since the president took office — though that number refers only to private sector employment gains over the past 29 months and leaves out state and local government jobs that continue to disappear each month.

Obama was back home in the White House after a campaign appearance in Virginia earlier in the day. He said he'd be watching on television when his wife spoke.

Appeals for cash

There was no end to the appeals for donations to his re-election campaign, falling further behind Romney in cash on hand with each passing month. "If you think Barack's the right man for the job, please show your support with a donation of $5 or more today," the first lady emailed supporters a little more than 90 minutes before her scheduled speech.

Polls made the race for the White House a tight one, almost certain to be decided in a string of eight or 10 battleground states where neither the president nor Romney holds a clear advantage. There was ample evidence of an underperforming economy, from a report that said manufacturing activity declined for a third straight month to a government announcement that the government's debt exceeded $16 trillion for the first time.

Castro, the first Hispanic chosen to deliver a keynote address, was unsparing in criticizing Romney, suggesting the former Massachusetts governor might not even be the driving force on the Republican ticket this fall.

"First they called it `trickle down, the supply side," he said of the economic proposals backed by Republicans. "Now it's Romney/Ryan. Or is it Ryan/Romney?"

Romney and the Republicans favor extension of all of the existing Bush-era tax cuts due to expire on Dec. 31, and also want to cut tax rates 20 per cent across the board.

Obama, too, wants to keep the existing tax cuts in place — except for people with earnings of $250,000 a year or more.

In the streets around the Democratic convention hall, police arrested 10 men and women who blocked an intersection in what they said was a protest of the nation's immigration laws. The 10 said they were illegal immigrants.

Romney under fire

Inside the arena, the convention hall cheered whenever Obama's image showed on the huge screen behind the speaker's podium, and roared when the late Sen. Edward M. Kennedy was shown mocking Romney in their 1994 Senate race.

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"On the issue of choice, I am pro-choice, my opponent is multiple choice," the late senator said as crowd grew louder.

Romney supported abortion rights while serving as governor; he generally opposes them now.

Democrats unspooled insult after insult as they took their turn the week after the Republicans had their convention in Tampa, Fla.

Illinois Gov. Pat Quinn said that Republicans had omitted mention of Romney's term as Massachusetts governor at their gathering.

"We already knew this extremely conservative man takes some pretty liberal deductions. Evidently that includes writing off all four years he served as governor," Quinn declared.

Said Senate Majority Leader Harry Reid of Nevada, speaking of Romney: "Never in modern American history has a presidential candidate tried so hard to hide himself from the people he hopes to serve."

"When you look at the one tax return he has released, it's obvious why there's been only one. We learned that he pays a lower tax rate than middle-class families. We learned he chose Swiss bank accounts and Cayman Island tax shelters over American institutions."

In his campaign trip to Virginia earlier in the day, Obama told an audience at Norfolk State University that the economy will get worse if Romney wins the White House this fall and that Election Day apathy was his enemy — and theirs.

Republicans are "counting on you, maybe not to vote for Romney, but they're counting on you to feel discouraged," he said. "And they figure if you don't vote, then big oil will write our energy future, and insurance companies will write our health care plans, and politicians will dictate what a woman can or can't do when it comes to her own health."